Age-related cognitive slowing: the role of spontaneous tempo and processing speed.

This research studied the relationships between two types of slowing observed in aging-loss of general processing speed and slowing of spontaneous tempo-in an attempt to test the assumption that there is an internal timing mechanism responsible for cognitive age-related decrease. Processing speed has been evaluated as a mediator of the relationship between age and working memory, concurrently with spontaneous tempo measures. The authors compared the performance of young and older adults on tasks involving spontaneous motor tempo, processing speed, and working memory. The findings confirmed the agerelated slowing of spontaneous motor tempo but did not indicate superiority of tempo mediation in the decline in working memory. Processing speed appeared to be a major mediator of working memory, but also of spontaneous tempo slowing.